Refrigerant additives and compositions

ABSTRACT

Embodiments are described herein to provide refrigerant and/or refrigerant composition that is suitable for providing lubrication to, for example, moving parts of a chiller system. Embodiments are also described herein to provide an additive, such as a corrosion inhibitor and/or stabilizers, that can be added to the refrigerant to form refrigerant compositions that is suitable for providing lubrication to, for example, moving parts of a chiller system.

FIELD

The disclosure herein relates to heating, ventilation, andair-conditioning (“HVAC”) systems, such as a chiller, and moreparticularly to a refrigerant composition of a chiller system, such as arefrigerant composition that may be suitable for lubricationapplications, and/or an oil-free HVAC system.

BACKGROUND

A HVAC system, such as a chiller, generally includes a compressor, acondenser, an evaporator and an expansion device. In a cooling cycle ofthe HVAC system, the compressor can compress refrigerant vapor, and thecompressed refrigerant vapor may be directed into the condenser tocondense into liquid refrigerant. The liquid refrigerant can then beexpanded by the expansion device and directed into the evaporator.

Components of the HVAC system, such as the compressor, may includemoving parts, and may require lubrication during operation. Lubricants,such as oil, are commonly used in the HVAC system to lubricate themoving parts.

SUMMARY

Embodiments are described herein to provide refrigerant and/orrefrigerant composition that is suitable for providing lubrication to,for example, moving parts of a chiller system. Embodiments are alsodescribed herein to provide an additive, such as a corrosion inhibitorand/or stabilizers, that can be added to the refrigerant to formrefrigerant compositions suitable for providing lubrication to, forexample, moving parts of a chiller system. The embodiments describedherein can be suitable for an oil-free chiller system, in which no oilis added to provide lubrication.

In some embodiments, the preferred refrigerants for providinglubrication, for example, in the chiller system can include arefrigerant or refrigerant blends of HCFC (Hydrochlorofluorocarbons),HFC (Hydrofluorocarbons), HCFO (Hydrochlorofluoroolefin), and/or HFO(Hydrofluoroolefins). For example, the refrigerant or refrigerant blendcan be at least one of or blends thereof of 1,1, dichloro-2,2,2trifluoroethane, 1,1,1,2 tetrafluoroethane, 1,1,1,3,3pentafluoropropane, difluromethane, 1,1 difluoroethane, 1-chloro-3,3,3trifluoropropene (E), 1-chloro-3,3,3 trifluoropropene (Z),2-chloro-3,3,3 trifluoropropene, 1,1,dichloro-3,3,3 trifluoropropene,2,3,3,3 tetrafluoropropene, 1,3,3,3 tetrafluoropropene (E), 1,3,3,3tetrafluoropropene (Z), 1,2 dichloro-3,3,3 trifluoropropene (E), 1,2dichloro-3,3,3 trifluoropropene (Z), 1,1,3 trichloro-3,3,3trifluoropropene, 1,2 dichloroethylene (E), 1,2 dichloroethylene (Z),1,1 dichloroethylene, 1,1,1,4,4,4 hexafluorobutene (Z), 1,1,1,4,4,4hexafluorobutene (E), 1,1,1,2,3 pentafluoropropane, 1,1,1,3,3pentafluoropropane, Isopentane, and pentane. In some embodiments, therefrigerant blend can be 1-chloro-3,3,3 trifluoroethene (E) with about10 to about 50% of 1,1,1,4,4,4 hexafluorobutene (E); 1-chloro-3,3,3trifluoroethene (E) with about 10 to about 50% of 1,1,1,2,3pentafluorobutane; 1-chloro-3,3,3 trifluoroethene (E) with about 10 toabout 50% of 1,1,1,3,3 pentafluorobutane; 1-chloro-3,3,3 trifluoroethene(E)with about 10 to about 50% of 1,1,2,2,3 pentafluorobutane;1,1,1,4,4,4 hexafluorobutene (E) with about 10 to about 50% of 1,1,1,2,3pentafluorobutane; 1,1,1,4,4,4 hexafluorobutene (E) with about 10 toabout 50% of 1,1,1,3,3 pentafluorobutane; or 1,1,1,4,4,4hexafluorobutene (E) with about 10 to about 50% of 1,1,2,2,3pentafluorobutane.

In some embodiments, an additive, such as a corrosion inhibitor and/or astabilizer can include at least one of or blends there of epoxides (suchas aromatic epoxides, alkyl epoxides, alkenyl epoxides), terpenes,terpenoids, fullerenes, ascorbic acid, terephthalate, nitromethane,unsaturated hydrocarbons or unsaturated halocarbons, phenols,perfluoropolyether, hindered phenols, hydroxylamines, thiols, phosphitesand lactones, siloxane, tolytriazoles, benzotriazole, amines, hydrazine,hexamine, phenylenediamine, dimethyethanolamine, zinc dithiophosphates,quaternary and acyclic amines, quaternized alkyl pyridine,amine/phosphate ester salt, cinnamaldehyde, dibutylamine,diethylhydroxylamine, dimethylethanolamine, 3,5 dinitrobenzoic acid,ethylenediamine, hexamethyleneteramine, 1,2 diaminopropane. It will beappreciated that the additive(s) and/or stabilizer(s) employed would besuitable and compatible for use with the refrigerant(s) of the system(s)and with the structural components of the system(s) itself.

In some embodiments, the additive may be added to the refrigerant inamounts of from about 0.001% to about 10%, more preferably from about0.01% to about 1% by a weight of the refrigerant. In one preferredembodiment, tolytriazoles and/or benzotriazole may be added to therefrigerant in a range of 0.001% to 0.5% by a weight of the refrigerant.In another preferred embodiment, hydroxylamines or dimethylethanol aminemay be added to the refrigerant in a range of 0.001% to 0.5% by a weightof the refrigerant.

Other features and aspects of the fluid management approaches willbecome apparent by consideration of the following detailed descriptionand accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a graph of the effects on refrigerant R123 viscosity asresult of pressure and temperature changes.

FIG. 2 shows another graph of the effects on refrigerant R134a viscosityas result of pressure and temperature changes.

DETAILED DESCRIPTION

A HVAC system, such as a chiller system, may commonly include componentswith moving parts, such as rollers and balls of a bearing of acompressor. The moving parts generally require proper lubrication. Thelubrication is commonly provided by lubricants, such as oil, to form aliquid lubricant layer to separate two surfaces of the moving parts thathave the relative movement. For example, to extend the service life of aroller bearing, the balls and the rollers of the bearing can be coatedwith a lubricant layer to separate the mating surfaces of the rollersand the balls so that the balls and the roller do not directly contactwith each other during operation.

In some HVAC systems, the lubrication can be provided by liquidrefrigerant. Such a HVAC system is sometimes called an oil-free system.In the oil-free system, liquid refrigerant can be directed to surfacesof the moving parts and form a liquid layer to separate two matingsurfaces of the moving parts. Issues of using refrigerant as a lubricantmay include poor boundary lubrication, which may in result contactbetween the two mating surfaces and a relatively high local temperaturedue to the contact. The relatively high temperature can break down therefrigerant, causing formation of, for example, highly aggressive acid(such as hydrofluoric and hydrochloric acid), refrigerant polymerizationand/or residue products. The acid may react with materials of the movingparts, causing corrosion of the moving parts. The refrigerantpolymerization and/or residue products can deposit on parts withcritical tolerances, such as orifices, seals and/or bearings, which mayalso lead to premature failure. Improvements can be made to refrigerantand/or refrigerant compositions that are suitable for providinglubrication, such as in an oil-free system.

Embodiments are described herein to provide refrigerant that is suitablefor providing lubrication to, for example, moving parts of a chillersystem. Embodiments are also described herein to provide an additive,such as a corrosion inhibitor and/or a stabilizer that can be added tothe refrigerant to form refrigerant compositions that are suitable forproviding lubrication to, for example, moving parts of a chiller system.For example, race and bearing surfaces may be formed of high martensiticstainless steel or other ball bearings that are of hot isostatic pressedsilicon nitride materials.

Mating surfaces of moving parts, such as the mating surfaces of a rollerand a ball, may contact each other during operation, causing an elevatedlocal temperature during operation. In some embodiments, the temperaturecan be between about 300° F. to about 1200° F. The refrigerant suitablefor providing lubrication may be relatively chemically stable attemperatures between about 300° F. to about 1200° F.

It is known in the art that when liquid refrigerant is used to providelubrication, a thickness of a liquid refrigerant layer on the matingsurfaces is affected by a pressure-viscosity coefficient of the liquidrefrigerant. The pressure-viscosity coefficient is an inherent propertyof the refrigerant. It measures a correlation between the viscosity ofthe refrigerant and the pressure at a given temperature. In someembodiments, the refrigerant that is suitable for providing lubricationmay have a viscosity of about 0.2 to 2 mPa. when the pressure is betweenabout 100 to 300 MPa and the temperature is between 25° C. to 100° C.See e.g. FIGS. 1 and 2 for examples of the effects on HCFC refrigerantR123 and HFC refrigerant R134a. It is to be appreciated that thepressure-viscosity coefficient of other refrigerants and/or refrigerantblends can be obtained.

It is appreciated that the refrigerant or refrigerant blend describedherein can have a suitable pressure-viscosity coefficient for providinglubrication in a HVAC system, which can include at least one of orblends thereof of 1,1, dichloro-2,2,2 trifluoroethane, 1,1,1,2tetrafluoroethane, 1,1,1,3,3 pentafluoropropane, difluromethane, 1,1difluoroethane, 1-chloro-3,3,3 trifluoropropene (E), 1-chloro-3,3,3trifluoropropene (Z), 2-chloro-3,3,3 trifluoropropene,1,1,dichloro-3,3,3 trifluoropropene, 2,3,3,3 tetrafluoropropene, 1,3,3,3tetrafluoropropene (E), 1,3,3,3 tetrafluoropropene (Z), 1,2dichloro-3,3,3 trifluoropropene (E), 1,2 dichloro-3,3,3 trifluoropropene(Z), 1,1,3 trichloro-3,3,3 trifluoropropene, 1,2 dichloroethylene (E),1,2 dichloroethylene (Z), 1,1 dichloroethylene, 1,1,1,4,4,4hexafluorobutene (Z), 1,1,1,4,4,4 hexafluorobutene (E), 1,1,1,2,3pentafluoropropane, 1,1,1,3,3 pentafluoropropane, Isopentane, andpentane. In some embodiments, the refrigerant blend having suitablepressure-viscosity coefficient for providing lubricating in a HVACsystem can be 1-chloro-3,3,3 trifluoroethene (E) with about 10 to about50% of 1,1,1,4,4,4 hexafluorobutene (E); 1-chloro-3,3,3 trifluoroethene(E) with about 10 to about 50% of 1,1,1,2,3 pentafluorobutane;1-chloro-3,3,3 trifluoroethene (E) with about 10 to about 50% of1,1,1,3,3 pentafluorobutane; 1-chloro-3,3,3 trifluoroethene (E)withabout 10 to about 50% of 1,1,2,2,3 pentafluorobutane; 1,1,1,4,4,4hexafluorobutene (E) with about 10 to about 50% of 1,1,1,2,3pentafluorobutane; 1,1,1,4,4,4 hexafluorobutene (E) with about 10 toabout 50% of 1,1,1,3,3 pentafluorobutane; or 1,1,1,4,4,4hexafluorobutene (E) with about 10 to about 50% of 1,1,2,2,3pentafluorobutane.

In some embodiments, the refrigerant may not chemically react to thematerial of the moving parts. In some embodiments, the refrigerant maynot chemically react to steel and/or chrome.

The preferred refrigerants for providing lubrication, for example, in achiller system can include at least one of or blends there of 1,1,dichloro-2,2,2 trifluoroethane, 1,1,1,2 tetrafluoroethane, 1,1,1,3,3pentafluoropropane, difluromethane, 1,1 difluoroethane, 1-chloro-3,3,3trifluoropropene (E), 1-chloro-3,3,3 trifluoropropene (Z),2-chloro-3,3,3 trifluoropropene, 1,1,dichloro-3,3,3 trifluoropropene,2,3,3,3 tetrafluoropropene, 1,3,3,3 tetrafluoropropene (E), 1,3,3,3tetrafluoropropene (Z), 1,2 dichloro-3,3,3 trifluoropropene (E), 1,2dichloro-3,3,3 trifluoropropene (Z), 1,1,3 trichloro-3,3,3trifluoropropene, 1,2 dichloroethylene (E), 1,2 dichloroethylene (Z),1,1 dichloroethylene, 1,1,1,4,4,4 hexafluorobutene (Z), 1,1,1,4,4,4hexafluorobutene (E), 1,1,1,2,3 pentafluoropropane, 1,1,1,3,3pentafluoropropane, Isopentane, and pentane.

In some embodiments, an additive or blend thereof, such as corrosioninhibitor(s) and/or a stabilizer(s) can be added to the refrigerant toprevent and/or reduce refrigerant breaking down. In some embodiments,the additive(s) may be one or more corrosion inhibitors, for example, achemical(s) that can be absorbed or bound to the surface of the movingparts (such as balls and/or rollers) of the bearings to prevent and/orreduce break down of the moving parts. The broken down material of themoving parts may work as a catalyst for refrigerant break down.Preventing and/or reducing break down of the moving parts can helpprevent and/or reduce refrigerant break down. In some embodiments, thecorrosion inhibitor can be a corrosion inhibitor for iron or coppercontaining material.

In some embodiments, one or more stabilizers, such as chemical(s) thatreact with the compounds resulting from refrigerant breaking down, canbe added to the refrigerant so as to reduce the amount of the compoundsresulting from the refrigerant breaking down. In some embodiments, thestabilizers (such as base, triazole) may react with acid resulting fromthe refrigerant breaking down so as to reduce the acid. In someembodiments, the stabilizer may react with oxygen that may be containedin the refrigerant to reduce the amount of oxygen contained in therefrigerant.

In some embodiments, the additive(s), such as the corrosion inhibitor(s)and/or the stabilizer(s), can be dissolved in the refrigerant. In someembodiments, the corrosion inhibitor and/or the stabilizer may benon-harmful to the environment. In some embodiments, the additive can beadded to the refrigerant in amounts of from about 0.001% to about 10%,more preferably from about 0.01% to about 1% by a weight of therefrigerant.

In some embodiments, the corrosion inhibitor and/or stabilizer caninclude at least one of or blends there of epoxides (such as aromaticepoxides, alkyl epoxides, alkenyl epoxides), terpenes, terpenoids,fullerenes, ascorbic acid, terephthalate, nitromethane, unsaturatedhydrocarbons or unsaturated halocarbons, phenols, perfluoropolyether,hindered phenols, hydroxylamines, thiols, phosphites and lactones,siloxane, tolytriazoles, benzotriazole, amines, hydrazine, hexamine,phenylenediamine, dimethyethanolamine, zinc dithiophosphates, quaternaryand acyclic amines, quaternized alkyl pyridine, amine/phosphate estersalt, cinnamaldehyde, dibutylamine, diethylhydroxylamine,dimethylethanolamine, 3,5 dinitrobenzoic acid, ethylenediamine,hexamethyleneteramine, 1,2 diaminopropane.

In one preferred embodiment, tolytriazoles and/or benzotriazole may beadded to the refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant. In another preferred embodiment, hydroxylamines and/ordimethylethanol amine may be added to the refrigerant in a range of0.001% to 0.5% by a weight of the refrigerant. The additive(s) can beadded to the refrigerant at the site of refrigerant manufacture or atthe site of chiller manufacturer. It will be appreciated that there arevarious ways to apply the additive(s), for example, including: directaddition to the refrigerant, e.g. the above materials can be addeddirectly to the refrigerant at the source of manufacture or addedseparately to the unit when the refrigerant is added or during serviceof the equipment; direct application to the bearings or other criticalparts, e.g. the above materials can be added directly to the partsthrough either a spray on or dip type application during themanufacturing of the equipment or during servicing of the equipment; andindirect application during manufacturing of sub components, e.g. theadditives can be applied during a secondary operation, like tube finningoperations or machining, when an additive is necessary to help withcorrosion, stabilization or machining lubrication during such processes,which can result in indirect contamination of the final unit assembly orduring service of the unit.

In some embodiments, the levels of the additive(s) can be monitored inthe field by obtaining a refrigerant sample and measuring the levels.And the levels can be adjusted by adding the additive(s).

Aspects

Any of aspects 1-8 can be combined with any of aspects 9-20. Any ofaspects 9-16 can be combined with any of aspects 17-20. Any of aspects17-18 can be combined with any of aspects 19-20. Aspect 19 can becombined with aspect 20.

Aspect 1. A refrigerant to provide lubrication in a HVAC system,comprising:

at least one refrigerant selected from a group including: 1,1,dichloro-2,2,2 trifluoroethane, 1,1,1,2 tetrafluoroethane, 1,1,1,3,3pentafluoropropane, difluromethane, 1,1 difluoroethane, 1-chloro-3,3,3trifluoropropene (E), 1-chloro-3,3,3 trifluoropropene (Z),2-chloro-3,3,3 trifluoropropene, 1,1,dichloro-3,3,3 trifluoropropene,2,3,3,3 tetrafluoropropene, 1,3,3,3 tetrafluoropropene (E), 1,3,3,3tetrafluoropropene (Z), 1,2 dichloro-3,3,3 trifluoropropene (E), 1,2dichloro-3,3,3 trifluoropropene (Z), 1,1,3 trichloro-3,3,3trifluoropropene, 1,2 dichloroethylene (E), 1,2 dichloroethylene (Z),1,1 dichloroethylene, 1,1,1,4,4,4 hexafluorobutene (Z), 1,1,1,4,4,4hexafluorobutene (E), 1,1,1,2,3 pentafluoropropane, 1,1,1,3,3pentafluoropropane, Isopentane, and pentane.

Aspect 2. The refrigerant of aspect 1, further comprising:

at least one additive selected from a group consisting of: epoxides,terpenes, terpenoids, fullerenes, ascorbic acid, terephthalate,nitromethane, unsaturated hydrocarbons or unsaturated halocarbons,phenols, perfluoropolyether, hindered phenols, hydroxylamines, thiols,phosphites and lactones, siloxane, tolytriazoles, benzotriazole, amines,hydrazine, hexamine, phenylenediamine, dimethyethanolamine, zincdithiophosphates, quaternary and acyclic amines, quaternized alkylpyridine, amine/phosphate ester salt, cinnamaldehyde, dibutylamine,diethylhydroxylamine, dimethylethanolamine, 3,5 dinitrobenzoic acid,ethylenediamine, hexamethyleneteramine, and 1,2 diaminopropane.

Aspect 3. The refrigerant of aspect 2, wherein the additive is added tothe refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant.

Aspect 4. The refrigerant of aspects 2-3, wherein the additive is addedto the refrigerant in a range of about 0.01% to about 1% by a weight ofthe refrigerant.

Aspect 5. The refrigerant of aspects 2-4, wherein tolytriazoles is addedto the refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant.Aspect 6. The refrigerant of aspects 2-5, wherein benzotriazole is addedto the refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant.Aspect 7. The refrigerant of aspects 2-6, wherein hydroxylamines isadded to the refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant.Aspect 8. The refrigerant of aspects 2-7, wherein dimethylethanol amineis added to the refrigerant in a range of 0.001% to 0.5% by a weight ofthe refrigerant.Aspect 9. A refrigerant blend to provide lubrication in a HVAC system,comprising 1,1, dichloro-2,2,2 trifluoroethane and at least onerefrigerant selected from: 1,1,1,2 tetrafluoroethane, 1,1,1,3,3pentafluoropropane, difluromethane, 1,1 difluoroethane, 1-chloro-3,3,3trifluoropropene (E), 1-chloro-3,3,3 trifluoropropene (Z),2-chloro-3,3,3 trifluoropropene, 1,1,dichloro-3,3,3 trifluoropropene,2,3,3,3 tetrafluoropropene, 1,3,3,3 tetrafluoropropene (E), 1,3,3,3tetrafluoropropene (Z), 1,2 dichloro-3,3,3 trifluoropropene (E), 1,2dichloro-3,3,3 trifluoropropene (Z), 1,1,3 trichloro-3,3,3trifluoropropene, 1,2 dichloroethylene (E), 1,2 dichloroethylene (Z),1,1 dichloroethylene, 1,1,1,4,4,4 hexafluorobutene (Z), 1,1,1,4,4,4hexafluorobutene (E), 1,1,1,2,3 pentafluoropropane, 1,1,1,3,3pentafluoropropane, Isopentane, and pentane.Aspect 10. The refrigerant blend of aspect 9, further comprising: atleast one additive selected from a group consisting of: epoxides,terpenes, terpenoids, fullerenes, ascorbic acid, terephthalate,nitromethane, unsaturated hydrocarbons or unsaturated halocarbons,phenols, perfluoropolyether, hindered phenols, hydroxylamines, thiols,phosphites and lactones, siloxane, tolytriazoles, benzotriazole, amines,hydrazine, hexamine, phenylenediamine, dimethyethanolamine, zincdithiophosphates, quaternary and acyclic amines, quaternized alkylpyridine, amine/phosphate ester salt, cinnamaldehyde, dibutylamine,diethylhydroxylamine, dimethylethanolamine, 3,5 dinitrobenzoic acid,ethylenediamine, hexamethyleneteramine, and 1,2 diaminopropane.Aspect 11. The refrigerant blend of aspect 10, wherein the additive isadded to the refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant.Aspect 12. The refrigerant blend of aspects 10-11, wherein the additiveis added to the refrigerant in a range of about 0.01% to about 1% by aweight of the refrigerant.Aspect 13. The refrigerant blend of aspects 10-12, wherein tolytriazolesis added to the refrigerant in a range of 0.001% to 0.5% by a weight ofthe refrigerant.Aspect 14. The refrigerant blend of aspects 10-13, wherein benzotriazoleis added to the refrigerant in a range of 0.001% to 0.5% by a weight ofthe refrigerant.Aspect 15. The refrigerant blend of aspects 10-14, whereinhydroxylamines is added to the refrigerant in a range of 0.001% to 0.5%by a weight of the refrigerant.Aspect 16. The refrigerant blend of aspects 10-15, whereindimethylethanol amine is added to the refrigerant in a range of 0.001%to 0.5% by a weight of the refrigerant.Aspect 17. An oil-Free HVAC system, comprising: 1,1, dichloro-2,2,2trifluoroethane; andat least one additive selected from a group consisting of: epoxides,terpenes, terpenoids, fullerenes, ascorbic acid, terephthalate,nitromethane, unsaturated hydrocarbons or unsaturated halocarbons,phenols, perfluoropolyether, hindered phenols, hydroxylamines, thiols,phosphites and lactones, siloxane, tolytriazoles, benzotriazole, amines,hydrazine, hexamine, phenylenediamine, dimethyethanolamine, zincdithiophosphates, quaternary and acyclic amines, quaternized alkylpyridine, amine/phosphate ester salt, cinnamaldehyde, dibutylamine,diethylhydroxylamine, dimethylethanolamine, 3,5 dinitrobenzoic acid,ethylenediamine, hexamethyleneteramine, and 1,2 diaminopropane.Aspect 18. The oil-free HVAC system of aspect 17, further comprising:

at least one refrigerant selected from a group including: 1,1,1,2tetrafluoroethane, 1,1,1,3,3 pentafluoropropane, difluromethane, 1,1difluoroethane, 1-chloro-3,3,3 trifluoropropene (E), 1-chloro-3,3,3trifluoropropene (Z), 2-chloro-3,3,3 trifluoropropene,1,1,dichloro-3,3,3 trifluoropropene, 2,3,3,3 tetrafluoropropene, 1,3,3,3tetrafluoropropene (E), 1,3,3,3 tetrafluoropropene (Z), 1,2dichloro-3,3,3 trifluoropropene (E), 1,2 dichloro-3,3,3trifluoropropene(Z), 1,1,3 trichloro-3,3,3 trifluoropropene, 1,2 dichloroethylene (E),1,2 dichloroethylene (Z), 1,1 dichloroethylene, 1,1,1,4,4,4hexafluorobutene (Z), 1,1,1,4,4,4 hexafluorobutene (E), 1,1,1,2,3pentafluoropropane, 1,1,1,3,3 pentafluoropropane, Isopentane, andpentane.

19. A refrigerant blend to provide lubrication in a HVAC system,comprising:

at least two refrigerants selected from a group including: 1,1,dichloro-2,2,2 trifluoroethane, 1,1,1,2 tetrafluoroethane, 1,1,1,3,3pentafluoropropane, difluromethane, 1,1 difluoroethane, 1-chloro-3,3,3trifluoropropene (E), 1-chloro-3,3,3 trifluoropropene (Z),2-chloro-3,3,3 trifluoropropene, 1,1,dichloro-3,3,3 trifluoropropene,2,3,3,3 tetrafluoropropene, 1,3,3,3 tetrafluoropropene (E), 1,3,3,3tetrafluoropropene (Z), 1,2 dichloro-3,3,3 trifluoropropene

(E), 1,2 dichloro-3,3,3 trifluoropropene (Z), 1,1,3 trichloro-3,3,3trifluoropropene, 1,2 dichloroethylene (E), 1,2 dichloroethylene (Z),1,1 dichloroethylene, 1,1,1,4,4,4 hexafluorobutene (Z), 1,1,1,4,4,4hexafluorobutene (E), 1,1,1,2,3 pentafluoropropane, 1,1,1,3,3pentafluoropropane, Isopentane, and pentane.

Aspect 20. A method of providing lubrication in an oil-free HVAC system,comprising:

providing 1,1, dichloro-2,2,2 trifluoroethane to mating surfaces of amoving part in the HVAC system.

With regard to the foregoing description, it is to be understood thatchanges may be made in detail, without departing from the scope of thepresent invention. It is intended that the specification and depictedembodiments are to be considered exemplary only, with a true scope andspirit of the invention being indicated by the broad meaning of theclaims.

1-20. (canceled)
 21. An oil-free refrigerant that provides lubricationin an HVAC system, comprising: at least one refrigerant selected fromthe group consisting of: 1,3,3,3 tetrafluoropropene (E) and 1,3,3,3tetrafluoropropene (Z).
 22. The refrigerant of claim 21, furthercomprising: at least one additive selected from a group consisting of:epoxides, terpenes, terpenoids, fullerenes, ascorbic acid,terephthalate, nitromethane, unsaturated hydrocarbons or unsaturatedhalocarbons, phenols, perfluoropolyether, hindered phenols,hydroxylamines, thiols, phosphites and lactones, siloxane,tolytriazoles, benzotriazole, amines, hydrazine, hexamine,phenylenediamine, dimethyethanolamine, zinc dithiophosphates, quaternaryand acyclic amines, quaternized alkyl pyridine, amine/phosphate estersalt, cinnamaldehyde, dibutylamine, diethylhydroxylamine,dimethylethanolamine, 3,5 dinitrobenzoic acid, ethylenediamine,hexamethyleneteramine, and 1,2 diaminopropane.
 23. The refrigerant ofclaim 22, wherein the additive is added to the refrigerant in a range of0.001% to 0.5% by a weight of the refrigerant.
 24. The refrigerant ofclaim 22, wherein the additive is added to the refrigerant in a range ofabout 0.01% to about 1% by a weight of the refrigerant.
 25. Therefrigerant of claim 22, wherein tolytriazoles is added to therefrigerant in a range of 0.001% to 0.5% by a weight of the refrigerant.26. The refrigerant of claim 22, wherein benzotriazole is added to therefrigerant in a range of 0.001% to 0.5% by a weight of the refrigerant.27. The refrigerant of claim 22, wherein hydroxylamines is added to therefrigerant in a range of 0.001% to 0.5% by a weight of the refrigerant.28. The refrigerant of claim 22, wherein dimethylethanol amine is addedto the refrigerant in a range of 0.001% to 0.5% by a weight of therefrigerant.
 29. An oil-free HVAC system, comprising: at least onerefrigerant selected from the group consisting of: 1,3,3,3tetrafluoropropene (E) and 1,3,3,3 tetrafluoropropene (Z); and at leastone additive selected from a group consisting of: epoxides, terpenes,terpenoids, fullerenes, ascorbic acid, terephthalate, nitromethane,unsaturated hydrocarbons or unsaturated halocarbons, phenols,perfluoropolyether, hindered phenols, hydroxylamines, thiols, phosphitesand lactones, siloxane, tolytriazoles, benzotriazole, amines, hydrazine,hexamine, phenylenediamine, dimethyethanolamine, zinc dithiophosphates,quaternary and acyclic amines, quaternized alkyl pyridine,amine/phosphate ester salt, cinnamaldehyde, dibutylamine,diethylhydroxylamine, dimethylethanolamine, 3,5 dinitrobenzoic acid,ethylenediamine, hexamethyleneteramine, and 1,2 diaminopropane.
 30. Amethod of providing lubrication in an oil-free HVAC system, comprising:providing the oil-free refrigerant of claim 21 to mating surfaces of amoving part in the HVAC system.